spritetest2.java

有关于java游戏编程的一本书

import java.awt.*;
import java.awt.geom.AffineTransform;
import javax.swing.ImageIcon;

public class SpriteTest2 {

    public static void main(String args[]) {
        SpriteTest2 test = new SpriteTest2();
        test.run();
    }

    private static final DisplayMode POSSIBLE_MODES[] = {
        new DisplayMode(800, 600, 32, 0),
        new DisplayMode(800, 600, 24, 0),
        new DisplayMode(800, 600, 16, 0),
        new DisplayMode(640, 480, 32, 0),
        new DisplayMode(640, 480, 24, 0),
        new DisplayMode(640, 480, 16, 0)
    };

    private static final long DEMO_TIME = 10000;
    private static final long FADE_TIME = 1000;
    private static final int NUM_SPRITES = 3;

    private ScreenManager screen;
    private Image bgImage;
    private Sprite sprites[];

    public void loadImages() {
        // load images
        bgImage = loadImage("images/background.jpg");
        Image player1 = loadImage("images/player1.png");
        Image player2 = loadImage("images/player2.png");
        Image player3 = loadImage("images/player3.png");

        // create and init sprites
        sprites = new Sprite[NUM_SPRITES];
        for (int i = 0; i < NUM_SPRITES; i++) {
            Animation anim = new Animation();
            anim.addFrame(player1, 250);
            anim.addFrame(player2, 150);
            anim.addFrame(player1, 150);
            anim.addFrame(player2, 150);
            anim.addFrame(player3, 200);
            anim.addFrame(player2, 150);
            sprites[i] = new Sprite(anim);

            // select random starting location
            sprites[i].setX((float)Math.random() *
                (screen.getWidth() - sprites[i].getWidth()));
            sprites[i].setY((float)Math.random() *
                (screen.getHeight() - sprites[i].getHeight()));

            // select random velocity
            sprites[i].setVelocityX((float)Math.random() - 0.5f);
            sprites[i].setVelocityY((float)Math.random() - 0.5f);
        }

    }


    private Image loadImage(String fileName) {
        return new ImageIcon(fileName).getImage();
    }


    public void run() {
        screen = new ScreenManager();
        try {
            DisplayMode displayMode =
                screen.findFirstCompatibleMode(POSSIBLE_MODES);
            screen.setFullScreen(displayMode);
            loadImages();
            animationLoop();
        }
        finally {
            screen.restoreScreen();
        }
    }


    public void animationLoop() {
        long startTime = System.currentTimeMillis();
        long currTime = startTime;

        while (currTime - startTime < DEMO_TIME) {
            long elapsedTime =
                System.currentTimeMillis() - currTime;
            currTime += elapsedTime;

            // update the sprites
            update(elapsedTime);

            // draw and update screen
            Graphics2D g = screen.getGraphics();
            draw(g);
            drawFade(g, currTime - startTime);
            g.dispose();
            screen.update();

            // take a nap
            try {
                Thread.sleep(20);
            }
            catch (InterruptedException ex) { }
        }

    }


    public void drawFade(Graphics2D g, long currTime) {
        long time = 0;
        if (currTime <= FADE_TIME) {
            time = FADE_TIME - currTime;
        }
        else if (currTime > DEMO_TIME - FADE_TIME) {
            time = FADE_TIME - DEMO_TIME + currTime;
        }
        else {
            return;
        }

        byte numBars = 8;
        int barHeight = screen.getHeight() / numBars;
        int blackHeight = (int)(time * barHeight / FADE_TIME);

        g.setColor(Color.black);
        for (int i = 0; i < numBars; i++) {
            int y = i * barHeight + (barHeight - blackHeight) / 2;
            g.fillRect(0, y, screen.getWidth(), blackHeight);
        }

    }


    public void update(long elapsedTime) {

        for (int i = 0; i < NUM_SPRITES; i++) {

            Sprite s = sprites[i];

            // check sprite bounds
            if (s.getX() < 0.) {
                s.setVelocityX(Math.abs(s.getVelocityX()));
            }
            else if (s.getX() + s.getWidth() >=
                screen.getWidth())
            {
                s.setVelocityX(-Math.abs(s.getVelocityX()));
            }
            if (s.getY() < 0) {
                s.setVelocityY(Math.abs(s.getVelocityY()));
            }
            else if (s.getY() + s.getHeight() >=
                screen.getHeight())
            {
                s.setVelocityY(-Math.abs(s.getVelocityY()));
            }

            // update sprite
            s.update(elapsedTime);
        }

    }


    public void draw(Graphics2D g) {
        // draw background
        g.drawImage(bgImage, 0, 0, null);

        AffineTransform transform = new AffineTransform();
        for (int i = 0; i < NUM_SPRITES; i++) {
            Sprite sprite = sprites[i];

            // translate the sprite
            transform.setToTranslation(sprite.getX(),
                sprite.getY());

            // if the sprite is moving left, flip the image
            if (sprite.getVelocityX() < 0) {
                transform.scale(-1, 1);
                transform.translate(-sprite.getWidth(), 0);
            }

            // draw it
            g.drawImage(sprite.getImage(), transform, null);
        }

    }

}